New 2C HK multistar batteries sneak peak (Double down)

[covert]

We all now about the new 10C multistar batteries that a making lithium powered bikes cheap for those of us don't mind dealing with the hassles hobby grade cells.

Today on the Hobbyking daily at 9.00 we get a sneak peak at the newer 2C batteries. The one shown is a 3S 12,000mHa 2C battery. Nick named the double down since it has close to twice the capacity for the same weight/size of the 10C multistar.

I run the Zippymax on the following list.

These figures are of my own spread sheet I keep. They could be completely wrong but the ratio would be right.
Zippymax 8000mAh 30C. @ 50 cents per watt. 7.12KG per 1000Wh
Ping 48V 15AH V2.5 LiFePO4 @ 74 cents per watt.10.42KG per 1000Wh
10C Multistar 10000mAh @ 46 cents per watt. 5.43KG per 1000Wh

Interesting to see how these new ones will fit in. At twice the density it could be 3KG per 1000Wh or less.

Link to YouTube Vid. https://www.youtube.com/watch?v=bNaiNNF7ZBs&index=3&list=PLBfWXKo6sbSmBAV8A36Hdeexafc1m_pOp

 

[Samd]

Nice work covert. I tend to find the zippys are about 10% overstated compared to Turnigys, but am keen to pack a frame soon with these new guys.
I was going to push the button last week - but someone bought them all!

 

[markz]

Isnt 2C like bottom of the barrel, I guess they are just hobby grade. What can the average ebiker user expect to get from a C-rate. And isnt HK stated C rate misinformation, I remember reading you take the stated C rate and half it for HK batteries.

 

[Punx0r]

333Wh/kg when the best 18650 energy cells are ~250Wh/kg? Seems fishy...

 

[\/ampa]

333Wh/kg when the best 18650 energy cells are ~250Wh/kg? Seems fishy...

It's quite possible after reading this http://www.gizmag.com/envia-systems-record-lithium-ion-battery/21653/
Maybe this will force the 18650 producers to step into Li-S chemistry.

 

[Samd]

I always wonder about the opportunity with cylindrical cells, as they contain about 23% air per unit volume when compared to bricks.

 

[mvly]

333Wh/kg when the best 18650 energy cells are ~250Wh/kg? Seems fishy...

It's quite possible after reading this http://www.gizmag.com/envia-systems-record-lithium-ion-battery/21653/
Maybe this will force the 18650 producers to step into Li-S chemistry.

If you read up on envia, they turned out to be scammer and I think they are currently being sued by multiple companies for stealing ideas as well as not being able to keep up their end of the stick when claiming such outrageous energy density.

Again over promising and under delivering. But I guess that is how the industry is. Sad... But true

 

[\/ampa]

I always wonder about the opportunity with cylindrical cells, as they contain about 23% air per unit volume when compared to bricks.

Cylindrical cells can be better temperature controlled and don't need to be compressed. They also are puncture resistant.

 

[Samd]

Cylindrical cells can be better temperature controlled and don't need to be compressed. They also are puncture resistant.

Yes, yes and yes.

I'm only coming at it from one dimension - density. Remove 23% air and you can put in 23% more stuff...

 

[covert]

333Wh/kg when the best 18650 energy cells are ~250Wh/kg? Seems fishy...

I just got some 4S 5200mHa 10C multistar, 433g on my scales. They work out to 177Wh/kg. Apparently these 2C ones are *close to half the weight so ~350Wh/kg at best. 333 is in the ballpark.

Looking forward to the specs when they come out.

 

[covert]

Isnt 2C like bottom of the barrel, I guess they are just hobby grade. What can the average ebiker user expect to get from a C-rate. And isnt HK stated C rate misinformation, I remember reading you take the stated C rate and half it for HK batteries.

C rating has nothing to do with the grade of the battery but low grade batteries tend to have low C ratings. At 2C a 12,000mHa battery will be good for 24Amps. More then enough for most commuter E-Bikes.

These Multistar Batteries are designed for Multicopters. People are hanging $1000's of dollars worth of gear under propellers being energized by these batteries. I think "Hobby grade" is a badly used term. If there was a "Bike Grade" it would be somewhere in the depth way under a Hobby grade. Your battery fails on your bike you peddle, Your Battery fails on a Flying Multicopter you potentially damages 1000's in dollars worth of gear.

 

[Punx0r]

If you assess most RC batteries based on their claimed spec (especially discharge rate) then they are very poor quality.

I doubt a battery supplier is likely to entertain a claim for consequential damage to a model and I doubt most hobbyists would expect them to.

 

[Sunder]

Any idea when these are coming out?

The main reason for me not carrying more range is not cost, it's weight and size.

 

[covert]

Sneak peaks to release seem to take a month or so on hoobyking. I'll be keen to try them out as soon as I can get some. Will post this thread as sson as I see them.